DESCRIPTION (provided the applicant): Although persons of Hispanic heritage represent the most rapidly growing segment of the U.S. population, this ethnic group remains among the most under-studied in the scientific community. Epidemiologists suggest that immigrants from Spanish-speaking countries are at increased risk for neurological disorders. Epilepsy is no exception. With the elevated incidence of epilepsy in Hispanic populations, comes an increased need for culturally-sensitive neuropsychological test measures appropriate for identifying the known cognitive sequelae of seizures and related disorders. Yet, upon testing, a variety of methodological and ecological factors place Hispanics at an inherent disadvantage, resulting in considerable disparities in test performance when compared to Anglo-Americans. Careful consideration of the factors underlying test bias is especially critical when evaluating candidates for epilepsy surgery. Failure to do so may obscure the patient's true pattern of deficit, resulting in potentially incorrect data interpretation and treatment recommendations. Despite the obvious threat to the accuracy and quality of care provided to Hispanic patients with epilepsy, no prior study has examined the diagnostic utility and psychometric properties of Spanish-language test measures appropriate for this context. In an effort to provide clinicians with well-validated, psychometrically-sound test batteries upon which to base their recommendations, the proposed study evaluates the predictive power, sensitivity, specificity, consistency, validity, and reliability of 2 available Spanish-language test batteries. Seventy-five Spanish-speaking Hispanic immigrants with epilepsy, 75 U.S.-born, Anglo-American English-speakers with epilepsy, and 75 neurologically-healthy Spanish-speaking immigrants will be administered two similar, yet linguistically appropriate, batteries of neuropsychological tests. In addition to comparing the diagnostic utility and psychometric properties of the tests themselves, we will also explore the role of culture-specific moderating variables.